1. Field
The present disclosure relates generally to an image forming apparatus, and more particularly, to a development apparatus that is used in an electro-photographic image forming apparatus.
2. Description of the Related Art
In general, an electro-photographic image forming apparatus, such as a laser printer, a facsimile machine, a copy machine, or the like, is a printing apparatus which forms an electrostatic latent image on an image carrier, develops the electrostatic latent image with a developing agent, and transfers a developer image onto a printing medium.
A developer that is used in the image forming apparatus includes an image carrier on which an electrostatic latent image is formed by an exposure unit and a developing member supplying a developing agent to the image carrier and developing the electrostatic latent image as a developer image. A method of developing the electrostatic latent image on the image carrier through the developing member may be classified into a contact type in which the developing member comes in contact with the image carrier and a non-contact type in which the developing member does not come in contact with the image carrier.
The contact type developer is so configured that a developing member 101 is separated from an image carrier 100 for a predetermined distance as illustrated in FIG. 1A before developing, and the developing member 101 moves in a direction B and comes in contact with the image carrier as illustrated in FIG. 1B during developing. Here, a reference numeral 103 denotes light that is emitted from an exposure unit. When the developing is finished, the developing member 101 is separated from the image carrier 100 for a predetermined distance as illustrated in FIG. 1A. Accordingly, when the developer is driven, a charging voltage is applied to a charging member 102, and the developing member 101 comes in contact with the image carrier 100 to be rotated. At this time, an outer circumference A of the image carrier 100 between the charging member 102 and the developing member 101 comes in contact with the developing member 101 in a non-charging state. When the non-charging section A of the image carrier 100 comes in contact with the developing member 101, the developing agent moves to the image carrier 100. Because of this, image pollution occurs due to the developing agent that has moved to the non-charging section A, and unnecessary consumption of the developing agent occurs to increase the waste developing agent.
In order to remove the developing agent that is attached to the non-charging section in the related art, cleaning blades are installed on the image carrier and a transfer belt. However, according to this method, it is required to prepare waste developing agent chambers having a space of a predetermined size for accommodating the waste developing agent therein on the sides of the image carrier and the transfer belt, and this causes the sizes of the developer and the image forming apparatus to be increased. Also, since the developing agent is attached to the non-charging section, the amount of consumption of the developing agent becomes larger. Accordingly, the maintenance cost is increased and the design of the developer is limited.
Also, according to the image forming apparatus in the related art, a zener diode is installed on the ground of the image carrier to heighten the electric potential of the non-charging section from 0V to −100 to −150V, and thus the non-charging section does not occur. However, this method has the problem that the material cost is increased due to the installation cost of the zener diode. Also, the deviation of the electric potential of the electrostatic latent image on the image carrier for each developer is increased due to the characteristic of the zener diode, and thus it is difficult to obtain a uniform image quality.